1. Field of the Invention
The present invention relates to a base for a motor and a hard disk drive including the same, and more particularly, to a base for a motor having an improved sealing function from the outside in a base manufactured by pressing process and a hard disk drive including the same.
2. Description of the Related Art
A hard disk drive (HDD), an information storage device of a computer, reads data stored on a disk by using a magnetic head or writes data on the disk.
In the hard disk drive, a head driving part that can reposition the magnetic head on the disk, i.e., a head stack assembly (HSA), is installed in a base and the magnetic head performs its own function while moving to a desired position while being positioned at a predetermined height above a recording surface of the disk by the head driving part.
In the related art, in manufacturing the base provided to the hard disk drive, the base is produced in a post-processing method in which aluminum (Al) is die-cast and thereafter, burrs generated by the die-casting are removed.
However, in the related art die-casting method, forging aluminum (Al) is injected into a mold in a molten state, and as a result, high energy is required for a process due to the requirements of high temperature and high pressure and a process period also increases.
Further, in terms of the lifespan of a die-casting mold, there is a limit in manufacturing a lot of bases with a single mold and the bases manufactured in the die-casting process may be inferior in size precision.
Therefore, the base is manufactured by using a pressing method in order to solve the problem in the die-casting process, but the bases manufactured by the pressing method may basically have a uniform thickness due to the characteristics of bending and cutting a plate material.
Further, an internal space of the hard disk drive (HDD) is sealed by a sealing member attached to the top of the base and the bottom of a cover in order to improve driving characteristics. Here, a contact area between the base and the sealing member becomes an important factor affecting sealing characteristics.
However, when the base is manufactured by using the pressing or forging method, an outer diameter and an outer width of the disk are determined according to an international standard, and as a result, the sizes of an inner wall and an outer wall of the hard disk drive maintaining a predetermined gap from the outer diameter of the disk are also standardized.
Under these limited conditions, when the base is manufactured by the pressing method, the inner wall and the outer wall should be manufactured by a bending process, and as a result, the top surface formed by the inner wall and the outer wall is rounded.
This may cause the contact area to be reduced at the time of attaching the sealing member to the base, and as a result, a sealing function may be deteriorated.
Accordingly, a study for securing a structure having the improved sealing function by overcoming a limit of the uniform thickness of the base even if the base is manufactured by the pressing method is urgent.